"the heat break stuck" doesn't really make any sense to me. I'm assuming you're getting some kind of jam after the first few layers? The most frequent cause of jams is either printing too fast for the temperature you're set at, or trying to print at too cold a temperature. I would try prin...

Just for grins, check your power supply output when the hotend and bed are both heating up. That's going to be where the max draw is happening. If it's less than 11.8-12v, you may have a power supply issue. If you've got one of the non-ATX supplies, there's an adjustment pot on it (where the termina...

You would slice with Cura and print from the SD card. Cura isn't really meant to be a printer host other than for Ultimaker printers. That being said, the network link from Cura to the Duet works great!

If the carriage is rocking, it's not due to any tolerance issue - you might have a broken carriage. That's the only way they're going to move in a way they shouldn't. The screw bosses can break over time if the carriage was slightly misaligned when it was screwed together - that's happened on two of...